/*
 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package java.io;

import java.lang.annotation.Native;

/**
 * Package-private abstract class for the local filesystem abstraction.
 */

abstract class FileSystem {

    /* -- Normalization and construction -- */

  /**
   * Return the local filesystem's name-separator character.
   */
  public abstract char getSeparator();

  /**
   * Return the local filesystem's path-separator character.
   */
  public abstract char getPathSeparator();

  /**
   * Convert the given pathname string to normal form.  If the string is
   * already in normal form then it is simply returned.
   */
  public abstract String normalize(String path);

  /**
   * Compute the length of this pathname string's prefix.  The pathname
   * string must be in normal form.
   */
  public abstract int prefixLength(String path);

  /**
   * Resolve the child pathname string against the parent.
   * Both strings must be in normal form, and the result
   * will be in normal form.
   */
  public abstract String resolve(String parent, String child);

  /**
   * Return the parent pathname string to be used when the parent-directory
   * argument in one of the two-argument File constructors is the empty
   * pathname.
   */
  public abstract String getDefaultParent();

  /**
   * Post-process the given URI path string if necessary.  This is used on
   * win32, e.g., to transform "/c:/foo" into "c:/foo".  The path string
   * still has slash separators; code in the File class will translate them
   * after this method returns.
   */
  public abstract String fromURIPath(String path);


    /* -- Path operations -- */

  /**
   * Tell whether or not the given abstract pathname is absolute.
   */
  public abstract boolean isAbsolute(File f);

  /**
   * Resolve the given abstract pathname into absolute form.  Invoked by the
   * getAbsolutePath and getCanonicalPath methods in the File class.
   */
  public abstract String resolve(File f);

  public abstract String canonicalize(String path) throws IOException;


    /* -- Attribute accessors -- */

  /* Constants for simple boolean attributes */
  @Native
  public static final int BA_EXISTS = 0x01;
  @Native
  public static final int BA_REGULAR = 0x02;
  @Native
  public static final int BA_DIRECTORY = 0x04;
  @Native
  public static final int BA_HIDDEN = 0x08;

  /**
   * Return the simple boolean attributes for the file or directory denoted
   * by the given abstract pathname, or zero if it does not exist or some
   * other I/O error occurs.
   */
  public abstract int getBooleanAttributes(File f);

  @Native
  public static final int ACCESS_READ = 0x04;
  @Native
  public static final int ACCESS_WRITE = 0x02;
  @Native
  public static final int ACCESS_EXECUTE = 0x01;

  /**
   * Check whether the file or directory denoted by the given abstract
   * pathname may be accessed by this process.  The second argument specifies
   * which access, ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE, to check.
   * Return false if access is denied or an I/O error occurs
   */
  public abstract boolean checkAccess(File f, int access);

  /**
   * Set on or off the access permission (to owner only or to all) to the file
   * or directory denoted by the given abstract pathname, based on the parameters
   * enable, access and oweronly.
   */
  public abstract boolean setPermission(File f, int access, boolean enable, boolean owneronly);

  /**
   * Return the time at which the file or directory denoted by the given
   * abstract pathname was last modified, or zero if it does not exist or
   * some other I/O error occurs.
   */
  public abstract long getLastModifiedTime(File f);

  /**
   * Return the length in bytes of the file denoted by the given abstract
   * pathname, or zero if it does not exist, is a directory, or some other
   * I/O error occurs.
   */
  public abstract long getLength(File f);


    /* -- File operations -- */

  /**
   * Create a new empty file with the given pathname.  Return
   * <code>true</code> if the file was created and <code>false</code> if a
   * file or directory with the given pathname already exists.  Throw an
   * IOException if an I/O error occurs.
   */
  public abstract boolean createFileExclusively(String pathname)
      throws IOException;

  /**
   * Delete the file or directory denoted by the given abstract pathname,
   * returning <code>true</code> if and only if the operation succeeds.
   */
  public abstract boolean delete(File f);

  /**
   * List the elements of the directory denoted by the given abstract
   * pathname.  Return an array of strings naming the elements of the
   * directory if successful; otherwise, return <code>null</code>.
   */
  public abstract String[] list(File f);

  /**
   * Create a new directory denoted by the given abstract pathname,
   * returning <code>true</code> if and only if the operation succeeds.
   */
  public abstract boolean createDirectory(File f);

  /**
   * Rename the file or directory denoted by the first abstract pathname to
   * the second abstract pathname, returning <code>true</code> if and only if
   * the operation succeeds.
   */
  public abstract boolean rename(File f1, File f2);

  /**
   * Set the last-modified time of the file or directory denoted by the
   * given abstract pathname, returning <code>true</code> if and only if the
   * operation succeeds.
   */
  public abstract boolean setLastModifiedTime(File f, long time);

  /**
   * Mark the file or directory denoted by the given abstract pathname as
   * read-only, returning <code>true</code> if and only if the operation
   * succeeds.
   */
  public abstract boolean setReadOnly(File f);


    /* -- Filesystem interface -- */

  /**
   * List the available filesystem roots.
   */
  public abstract File[] listRoots();

  /* -- Disk usage -- */
  @Native
  public static final int SPACE_TOTAL = 0;
  @Native
  public static final int SPACE_FREE = 1;
  @Native
  public static final int SPACE_USABLE = 2;

  public abstract long getSpace(File f, int t);

    /* -- Basic infrastructure -- */

  /**
   * Compare two abstract pathnames lexicographically.
   */
  public abstract int compare(File f1, File f2);

  /**
   * Compute the hash code of an abstract pathname.
   */
  public abstract int hashCode(File f);

  // Flags for enabling/disabling performance optimizations for file
  // name canonicalization
  static boolean useCanonCaches = true;
  static boolean useCanonPrefixCache = true;

  private static boolean getBooleanProperty(String prop, boolean defaultVal) {
    String val = System.getProperty(prop);
    if (val == null) {
      return defaultVal;
    }
    if (val.equalsIgnoreCase("true")) {
      return true;
    } else {
      return false;
    }
  }

  static {
    useCanonCaches = getBooleanProperty("sun.io.useCanonCaches",
        useCanonCaches);
    useCanonPrefixCache = getBooleanProperty("sun.io.useCanonPrefixCache",
        useCanonPrefixCache);
  }
}
